This invention relates to a method and apparatus for processing paper.
More particularly, the invention relates to a method and apparatus for processing a strip of paper into two streams of cut sheets and for collating the streams.
In a further respect, the invention pertains to a method and apparatus which facilitates the collating of two streams of separate sheets of paper by laterally displacing sheets in one stream into registration with sheets in the other stream while maintaining a constant speed of movement of both streams in a selected direction of travel.
In another respect, the invention pertains to a method and apparatus which facilitates the collating of two streams by producing sheets of differing length in either or both streams.
A prior art method for processing a strip of paper 10 to cut and collate pages formed on the strip of paper is illustrated in FIG. 1. In FIG. 1, paper strip 10 has a width indicated by arrows W and includes longitudinal centerline 21 and laterally extending lines of weakening 11 formed at equal intervals therealong. The lines of weakening 11 can comprise imperforate lines, can comprise line formed by die cutting part way through strip 10, can comprise imprinted lines, can comprise imaginary lateral lines which pass through a timing mark or some other mark on strip 10, or can simply comprise locations which can be identified by equipment which processes strip 10. Information, for example alphanumeric characters 22 and 23, is formed on strip 10. The information is formed by printing or any other desired means and typically comprises alphanumeric characters, illustrations, or any other desired data or forms. The information is formed on strip 10 in locations which anticipate that strip 10 will be cut into equal sized separate sheets or pages which comprise multiple documents or "jobs" and that the separate sheets or pages will be collated and stacked. As used herein, the term paper is understood to include thin sheets of material upon which alphanumeric characters, illustrations, etc. can be formed. While such material normally comprises a cellulose composition, plastics, fabrics or other materials can be utilized.
At point A in FIG. 1, a cutting apparatus slits strip 10 along its longitudinal centerline 21 to form a pair of supplemental paper strips 13 and 14.
At point B in FIG. 1, collating of supplemental paper strips 13 and 14 begins.
At point C in FIG. 1, supplemental paper strips are fully collated into registration with one another.
At point D in FIG. 1, collated supplemental paper strips are cut along lines of weakening 11 to form discrete stacks of paper each comprised of a pair of pages or sheets.
At point E in FIG. 1, a stacked pair of pages 15 and 16 is illustrated. Each sequential stacked pair of pages ordinarily is stacked on top of the preceding previously stacked pairs of pages which comprise a document. Once all of the pages in a document are stacked, or separated from other cut pairs of sheet produced by the method of FIG. 1, then a new stack of separated page pairs is begun which comprises another document. Such stacking and separating of documents can be done manually or with equipment.
The prior art process illustrated in FIG. 1 has disadvantages. First, the process of FIG. 1 stacks and separate pairs 15, 16 of sheets or pages. If a document includes an odd number of pages, then a blank or "waste" page ordinarily is formed on strip 10 adjacent the last page of the document. Second, the process of FIG. 1 has no provision for separating out prior to collating and stacking a single page from the processing stream. Third, if one large stack of sheets including multiple documents is formed using the process of FIG. 1, there is no easy way to determine quickly the location of each document in the stack.
Accordingly, it would be highly desirable to provide an improved method and apparatus which would cut and collate pages in a strip of paper such that waste blank pages would not have to be included on a strip of paper being cut and collated, such that designated sheets could be removed from a stream of cut sheets, and such that the location of documents in the stack could be readily determined.
Therefore, it is a principal object of the invention to provide an improved method and apparatus for separating a strip of paper containing multiple documents into cut sheets and for collating the cut sheets.
A further object of the invention is to provide an improved method and apparatus for processing a paper strip into a stack of paper sheets comprising multiple documents such that the location of each document in the stack can be readily identified.
Another object of the invention is to provide an improved method and apparatus for processing a paper strip which facilitates the location of each sheet imprinted on the paper strip so that selected sheets can be cut from the strip having lengths different from other sheets in the strip.
Yet another object of the invention is to provide an improved method and apparatus for processing a paper strip into a stream of sheets which enables selected pages to be removed from the stream of sheets before the sheets are collated and stacked.
These and other, further and more specific objects and advantages of the invention will be apparent to those skilled in the art from the following detailed description thereof, taken in conjunction with the drawings, in which: